1. Field of the Invention
The present invention relates to a MEMS (Micro electro Mechanical system) device using an actuator.
2. Description of the Related Art
Conventionally, a MEMS variable capacitor using an actuator has top and bottom electrodes. The top or bottom electrode is vertically varied by the actuator, and thereby, functions as a variable capacitor. For example, the bottom electrode is arranged on a substrate while the top electrode is attached to the actuator, and the top electrode is vertically varied. The MEMS variable capacitor having the foregoing structure has the following problem. The top electrode attached to the actuator is bent due to residual stress of a film itself forming the top electrode. In this case, the top electrode is bent to a direction (hereinafter, referred to as upward) opposite to the bottom electrode, or to the bottom electrode direction (hereinafter, referred to as downward). For this reason, in the initial state that the actuator is not driven, the top electrode is set to an unsuitable position, and the position of the top electrode is displaced.